Re: [RFC-PATCH 1/2] mm: Add __GFP_NO_LOCKS flag

From: Paul E. McKenney
Date: Fri Aug 14 2020 - 11:26:27 EST


On Fri, Aug 14, 2020 at 12:23:06PM +0200, peterz@xxxxxxxxxxxxx wrote:
> On Fri, Aug 14, 2020 at 10:30:37AM +0200, Peter Zijlstra wrote:
> > > > 1. Prohibit invoking allocators from raw atomic context, such
> > > > as when holding a raw spinlock.
> > >
> > > Clearly the simplest solution but not Pauls favourite and
> > > unfortunately he has a good reason.
> >
> > Which isn't actually stated anywhere I suppose ?
>
> Introduce raw_kfree_rcu() that doesn't do the allocation, and fix the
> few wonky callsites.

The problem with that is common code along with the tendency of people
to just use the one that "works everywhere".

Thanx, Paul